Our goals for the current year are to evaluate the effect of cephalic vagal stimulation by sham feeding on gastric acid secretion and serum gastrin concentration; to study the interactions between cephalic vagal stimulation, gastric distention with saline and gastric distention with food; to evaluate the physiological importance of gastrin (G-17) in the acid secretory response to amino acid solutions; to evaluate the effect of cephalic vagal stimulation by sham feeding on human pancreatic polypeptide concentration; to study the effect of varying degrees of gastric distention on acid secretion; and to compare the effect of a low dose anticholinergic, maximum tolerated dose anticholinergic, and cimetidine on food stimulated acid secretion and serum gastrin concentration.